Passenger Seat Rattle - 2018 CRV EXL
The passenger seat makes a rattle sound. I found that it was the seat, by thumping the upper portion of the seat in such a way that would send it towards the door/window, and then back towards me. The seat seems to have a rattle effect from left to right. This is also caused by normal road vibrations.
This was a mystery rattle to me that i had previously assumed was coming from the passenger side seat belt height adjustment area. It does not seem to be the floor mount of the seat, but instead seems to my experiments to be the upper portion of the seat.
Sharing in case this is a mystery for anyone else, or if you have any information.